maize
GM maize, health and the Séralini affair
Smelling a rat
GENETICALLY modified maize causes cancer: that was the gist of a study, among the most controversial in recent memory, published in September 2012 in the journal, Food and Chemical Toxicology. Well, actually, it doesn’t. The journal has just retracted the article. It would be too much to say that GM foods have therefore been proven safe. But no other study has so far found significant health risks in mammals as a result of eating GM foods.
The article in question was by Gilles-Eric Séralini of the University of Caen and colleagues. It describes what happened to rats fed with NK103 maize, a variety that is resistant to a herbicide called Roundup, as a result of genetic modification by Monsanto, an American plant-science firm. Because the crop has resistance, farmers can spray their fields with Roundup, killing the weeds but leaving the maize unscathed. In Dr Séralini’s experiment, rats fed with the modified maize were more likely to develop tumours than those which had not. Female rats were especially badly affected: their death rates were two or three times higher than those of control groups. Rats fed with diluted Roundup also suffered health damage.
The article was explosive. The French prime minister said that, if its results were confirmed, his government would press for a European-wide ban on NK103 maize. Russia suspended imports of the corn. Kenya banned all GM crops. The article came out two months before a referendum in California that would have required the labelling of all GM foods. It played a role in the vote, though in the event the proposition was defeated.
The paper had all the more impact because it contradicted previous studies. A paper in 2007 by Japan’s Department of Environmental Health and Toxicology had reported “no apparent adverse effect in rats” from NK103 maize and Roundup. That finding had been confirmed by a review of all the evidence by a team at the University of
Smelling a rat
GENETICALLY modified maize causes cancer: that was the gist of a study, among the most controversial in recent memory, published in September 2012 in the journal, Food and Chemical Toxicology. Well, actually, it doesn’t. The journal has just retracted the article. It would be too much to say that GM foods have therefore been proven safe. But no other study has so far found significant health risks in mammals as a result of eating GM foods.
The article in question was by Gilles-Eric Séralini of the University of Caen and colleagues. It describes what happened to rats fed with NK103 maize, a variety that is resistant to a herbicide called Roundup, as a result of genetic modification by Monsanto, an American plant-science firm. Because the crop has resistance, farmers can spray their fields with Roundup, killing the weeds but leaving the maize unscathed. In Dr Séralini’s experiment, rats fed with the modified maize were more likely to develop tumours than those which had not. Female rats were especially badly affected: their death rates were two or three times higher than those of control groups. Rats fed with diluted Roundup also suffered health damage.
The article was explosive. The French prime minister said that, if its results were confirmed, his government would press for a European-wide ban on NK103 maize. Russia suspended imports of the corn. Kenya banned all GM crops. The article came out two months before a referendum in California that would have required the labelling of all GM foods. It played a role in the vote, though in the event the proposition was defeated.
The paper had all the more impact because it contradicted previous studies. A paper in 2007 by Japan’s Department of Environmental Health and Toxicology had reported “no apparent adverse effect in rats” from NK103 maize and Roundup. That finding had been confirmed by a review of all the evidence by a team at the University of